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arXiv:gr-qc/0410030 · Physical Review A

Testing quantum superpositions of the gravitational field with Bose-Einstein condensates

Netanel H. Lindner, Asher Peres

Published Feb 7, 2005• 27 citations
arXivHTMLPDF

Abstract

We consider the gravity field of a Bose-Einstein condensate in a quantum superposition. The gravity field then is also in a quantum superposition, which is in principle observable. Hence we have ``quantum gravity'' far away from the so-called Planck scale.
DOI
10.1103/physreva.71.024101

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Light-pulse atom interferometers are highly sensitive to inertial and gravitational effects. As such they are promising candidates for tests of gravitational physics. In this article the state-of-the-art and proposals for fundamental tests of gravity are reviewed. They include the measurement of the gravitational constant GGG, tests of the weak equivalence principle, direct searches of dark energy and gravitational-wave detection. Particular emphasis is put on long-time interferometry in microgravity environments accompanied by an enormous increase of sensitivity. In addition, advantages as well as disadvantages of Bose-Einstein condensates as atom sources are discussed.
The free expansion of a Bose–Einstein condensate is analyzed, assuming that the single particle energy spectrum is modified due to some quantum structure of space time. The condensate’s free velocity expansion leads in a natural way to a deformed uncertainty principle. We show that large expansion times are required in order to amplify some possible traces of the Planck scale regime. The analysis presented in this work opens up the opportunity to use Bose–Einstein condensates as tools in quantum gravity phenomenology with a solid experimental basis.